Optoelectronic tweezer device and fabrication method thereof

ABSTRACT

An optoelectronic tweezer device includes a transparent substrate, a semiconductor layer, a first electrode and a dielectric layer. The semiconductor layer is located above the transparent substrate and includes a first doping region, a second doping region and a transition region, wherein the transition region is located between the first doping region and the second doping region. The first electrode is located on the first doping region and is electrically connected to the first doping region. The dielectric layer is located above the semiconductor layer and has a first through hole overlapping the first electrode.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Taiwan applicationserial no. 111103180, filed on Jan. 25, 2022. The entirety of theabove-mentioned patent application is hereby incorporated by referenceherein and made a part of this specification.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The invention relates to an optical tweezer device and fabricationmethod thereof.

2. Description of Related Art

Optical tweezer is a tool for operating tiny particles such assemiconductor particles, metal particles, metal nanowires, biologicalcells or other particles. In general, the operation of optical tweezercan be performed by a highly focused laser beam. Nanoscale or microscaledielectric particles can be operated by the force generated by the laserbeam. Optical tweezer operates in a non-mechanical contact manner, andthe damage to the particles to be clamped by the optical tweezer can bereduced by selecting a suitable wavelength of laser light. Therefore,there are many biotechnological studies using the optical tweezer tooperate single cells.

SUMMARY OF THE INVENTION

The present invention provides an optical tweezer device, which canreduce the cost of the manufacturing process.

The invention provides a manufacturing method of an optical tweezerdevice, which can reduce the production cost of the optical tweezerdevice.

At least one embodiment of the present invention provides an opticaltweezer device including a transparent substrate, a semiconductor layer,a first electrode and a dielectric layer. The semiconductor layer islocated above the transparent substrate and includes a first dopingregion, a second doping region and a transition region, wherein thetransition region is located between the first doping region and thesecond doping region. The first electrode is located on the first dopingregion and is electrically connected to the first doping region. Thedielectric layer is located on the semiconductor layer and has a firstthrough hole overlapping the first electrode.

At least one embodiment of the present invention provides a method formanufacturing an optical tweezer device, including: forming asemiconductor material layer above a transparent substrate; performing aplurality of doping processes on the semiconductor material layer toform a semiconductor layer including a first doping region, a seconddoping region and a transition region, wherein the transition region islocated between the first doping region and the second doping region;forming a first electrode on the first doping region; and forming adielectric layer over the semiconductor layer, the dielectric layer hasa first through hole overlapping the first electrode.

Based on the above, since the semiconductor layer is located on thetransparent substrate, the semiconductor layer can be formed by a thinfilm process, thereby reducing the production cost of the opticaltweezer device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic cross-sectional view of an optical tweezer deviceaccording to an embodiment of the present invention.

FIG. 1B is a schematic top view of the optical tweezer device of FIG.1A.

FIG. 2 is a schematic cross-sectional view of an optical tweezer deviceaccording to an embodiment of the present invention.

FIG. 3A to FIG. 9A, FIG. 10 , FIG. 11 and FIG. 12 are schematiccross-sectional views of a method for manufacturing an optical tweezerdevice according to an embodiment of the present invention.

FIG. 3B to 9B are schematic top views of the structures of FIG. 3A toFIG. 9A.

FIG. 13A is a schematic cross-sectional view of an optical tweezerdevice according to an embodiment of the present invention.

FIG. 13B is a schematic top view of the optical tweezer device of FIG.13A.

FIG. 14A is a schematic cross-sectional view of an optical tweezerdevice according to an embodiment of the present invention.

FIG. 14B is a schematic top view of the optical tweezer device of FIG.14A.

FIG. 15A is a schematic cross-sectional view of an optical tweezerdevice according to an embodiment of the present invention.

FIG. 15B is a schematic top view of the optical tweezer device of FIG.15A.

DESCRIPTION OF THE EMBODIMENTS

FIG. 1A is a schematic cross-sectional view of an optical tweezer deviceaccording to an embodiment of the present invention. FIG. 1B is aschematic top view of the optical tweezer device of FIG. 1A, whereinFIG. 1A corresponds to the position of the line a-a′ in FIG. 1B. FIG. 1Bshows the first electrodes E1, the second electrode E2, the transitionregion 114 of the semiconductor layer 110 and the first through hole 132of the dielectric layer 130, and other components are omitted in FIG.1B.

Referring to FIG. 1A and FIG. 1B, the optical tweezer device 10 includesa transparent substrate 100, a semiconductor layer 110, first electrodesE1 and a dielectric layer 130. In this embodiment, the optical tweezerdevice 10 further includes a second electrode E2, an insulation layer120, a buffer solution 200, a plurality of particles 300, a counterelectrode 400, a reflective layer 510 and a protection layer 520. Insome embodiments, the optical tweezer device 10 is a Self lockingoptical tweezer (SLOT) device.

The material of the transparent substrate 100 includes, for example,glass, quartz, organic polymer or other suitable materials. Comparedwith using a silicon wafer as the substrate, the use of the transparentsubstrate 100 can reduce the production cost of the optical tweezerdevice 10.

The semiconductor layer 110 is located above the transparent substrate100. In some embodiments, the material of the semiconductor layer 110includes, for example, polysilicon, amorphous silicon, single crystalsilicon or other suitable materials. The semiconductor layer 110includes first doping regions 112, second doping region 116 andtransition regions 114, wherein the transition regions 114 are locatedbetween the first doping regions 112 and the second doping region 116.

The first doping regions 112 are separated from each other. In someembodiments, the first doping regions 112 are arrayed on the transparentsubstrate 100, for example, the vertical projection of a first dopingregion 112 on the transparent substrate 100 is a circle, an ellipse, atriangle, a rectangle, pentagon, hexagon or other geometric shapes, andthe first doping regions 112 are arrayed on the transparent substrate100 along the first direction D1 and the second direction D2. FIG. 1Ashows two first doping regions 112 in the optical tweezer device 10, butthe number of the first doping regions 112 can be adjusted according toactual needs. In some embodiments, the width W1 of the first dopingregion 112 is 2 μm to 100 μm.

The transition regions 114 are separated from each other, and eachtransition region 114 surrounds a corresponding one of the first dopingregions 112. In some embodiments, the transition region 114 and thefirst doping region 112 are concentric circles, but the invention is notlimited thereto. In other embodiments, the first doping region 112 mayinclude shapes other than circular, and the shape of the transitionregion 114 varies with the shape of the first doping region 112. In someembodiments, the width W2 of the transition region 114 is 2 μm to 20 μm.

The second doping region 116 surrounds the plurality of transitionregions 114. In this embodiment, the second doping region 116 is acontinuous structure, and the transition regions 114 and the firstdoping regions 112 are distributed in the second doping region 116.

In some embodiments, one of the first doping region 112 and the seconddoping region 116 is a P-type semiconductor, and the other of the firstdoping region 112 and the second doping region 116 is an N-typesemiconductor, and the transition region 114 is an intrinsicsemiconductor or a lightly doped semiconductor which has a purity closeto the intrinsic semiconductor. Therefore, the semiconductor layer 110includes a plurality of PIN diodes consisting of the first dopingregions 112, the transition regions 114 and the second doping region116.

The insulation layer 120 is located on the semiconductor layer 110. Theinsulation layer 120 has a plurality of openings O1 and O2 overlappingthe semiconductor layer 110. The openings O1 overlap the first dopingregions 112, and the opening O2 overlap the second doping region 116. Insome embodiments, the sidewalls of the openings O1 are substantiallyaligned with the boundary of the first doping regions 112, but theinvention is not limited thereto. In other embodiments, the sidewalls ofthe openings O1 are deviated from the boundary of the first dopingregions 112. The material of the insulation layer 120 includes, forexample, silicon oxide, silicon nitride, silicon oxynitride or othersuitable materials.

In some embodiments, the first electrodes E1 are arrayed on thesemiconductor layer 110 along the first direction D1 and the seconddirection D2, but the invention is not limited thereto. In otherembodiments, the first electrodes E1 are arrayed on the semiconductorlayer 110 in other arrangements. The first electrodes E1 are located onthe first doping regions 112 and are electrically connected to the firstdoping regions 112. In this embodiment, the first electrodes E1 isdirectly formed on the first doping regions 112. In this embodiment, thefirst electrodes E1 are island-shaped structures, and each of the firstelectrodes E1 overlaps a corresponding one of the first doping regions112. In some embodiments, the sidewalls of the first electrodes E1 aresubstantially aligned with the boundary of the first doping regions 112,but the invention is not limited thereto. In other embodiments, thesidewalls of the first electrodes E1 deviate from the boundary of thefirst doping regions 112.

The second electrode E2 is located on the second doping region 116 andis electrically connected to the second doping region 116. In thisembodiment, the second electrode E2 is directly formed on the seconddoping region 116. In this embodiment, the second electrode E2 is acontinuous structure, and the second electrode E2 surrounds theisland-shaped first electrodes E1. In some embodiments, the sidewalls ofthe second electrodes E2 are substantially aligned with the boundary ofthe second doping region 116, but the invention is not limited thereto.In other embodiments, the sidewalls of the second electrode E2 deviatefrom the boundary of the second doping region 116.

The first electrode E1 may have a single-layer or multi-layer structure.The material of the first electrodes E1 include metal, metal oxide,metal nitride or other suitable materials. The second electrode E2 mayhave a single-layer or multi-layer structure. The material of the secondelectrode E2 includes metal, metal oxide, metal nitride or othersuitable materials. In some embodiments, the first electrodes E1 and thesecond electrode E2 belong to the same conductive layer. In other words,the first electrodes E1 and the second electrode E2 are formed bypatterning the same conductive material layer. In some embodiments, thefirst electrodes E1 and the second electrode E2 include the samethickness and the same material.

The dielectric layer 130 is located above the semiconductor layer 110.In this embodiment, the dielectric layer 130 is formed on the firstelectrodes E1, the second electrode E2 and the insulation layer 120, andpart of the first electrodes E1, the second electrode E2 and theinsulation layer 120 are located between the semiconductor layer 110 andthe dielectric layer 130. The dielectric layer 130 covers the topsurface of the second electrode E2. The dielectric layer 130 has firstthrough holes 132 overlapping the first electrodes E1. In someembodiments, the material of the dielectric layer 130 includes siliconoxide, silicon nitride, silicon oxynitride, organic materials or othersuitable materials.

The first through holes 132 expose at least part of the top surface ofthe first electrodes E1. In this embodiment, the dielectric layer 130has a plurality of first through holes 132 arranged in an array, andeach of the first through holes 132 overlaps with a corresponding one ofthe first electrodes E1. In some embodiments, the width W3 of the firstthrough hole 132 is 2 μm to 100 μm.

The reflective layer 510 is located on the side of the transparentsubstrate 100 facing away from the semiconductor layer 110. Thetransparent substrate 100 is located between the reflective layer 510and the semiconductor layer 110. In some embodiments, the reflectivelayer 510 includes metal or other reflective material. The protectionlayer 520 covers the reflective layer 510.

The counter electrode 400 overlaps the plurality of first electrodes E1.In some embodiments, the counter electrode 400 includes a material thatcan transmit light, such as indium tin oxide, indium zinc oxide,aluminum tin oxide, aluminum zinc oxide, indium gallium zinc oxide,organic conductive material, or other suitable material or stackedlayers of the above materials.

The buffer solution 200 is located between the counter electrode 400 andthe first electrodes E1. The buffer solution 200 is located between thecounter electrode 400 and the dielectric layer 130. In some embodiments,the buffer solution 200 fills the first through holes 132 of thedielectric layer 130, and the buffer solution 200 is in contact with thecounter electrode 400, the first electrodes E1 and the dielectric layer130. In some embodiments, the buffer solution 200 is, for example, aphysiological buffer solution or other buffer solution (e.g., anisotonic buffer solution). A plurality of particles 300 are located inthe buffer solution 200. The particles 300 may be biological particles,organic particles, or inorganic particles. The particle size of theparticles 300 is 2 μm to 100 μm.

In some embodiments, alternating current is applied to the counterelectrode 400 and the first electrodes E1 at a frequency to generate anelectric field between the counter electrode 400 and the firstelectrodes E1. The induced polarized particles 300 are attracted to thefirst through holes 132 of the dielectric layer 130 overlapping thefirst electrodes E1 due to the dielectrophoretic force.

Referring to FIG. 2 , a desired induced polarized particle 300 areselected, and the position of the selected induced polarized particle300 (or the position of the semiconductor layer 110 under the selectedinduced polarized particle 300) is irradiated with the light beam LS. Insome embodiments, the diameter of the light beam LS is larger than thewidth of the first electrode E1, and the light beam LS not onlyirradiates the induced polarized particle 300, but also irradiates thePIN diode under the selected first electrode E1. The diameter of thelight beam LS is 2 μm to 120 μm. For example, the light beam LSirradiates the transition region 114, causing the PIN diode below theselected induced polarized particle 300 to generate a photocurrent, andreverses the direction of the dielectrophoretic force of the selectedinduced polarized particle 300, so that the selected induced polarizedparticle 300 is repelled and exits the first through hole 132 of thedielectric layer 130. In some embodiments, the buffer solution 200 flowsalong the flow direction LF, and thus, the induced polarized particle300 exiting the first through hole 132 flows downstream along the buffersolution 200. In some embodiments, the induced polarized particle 300flowing downstream are collected and analysed, but the invention is notlimited thereto. In other embodiments, the induced polarized particles300 retained on the first through holes 132 are collected and analysed.

In some embodiments, the light beam LS includes laser, ultravioletlight, visible light, or other suitable light.

In some embodiments, since the optical tweezer device 10 includes thereflective layer 510, the light beam LS passing through the transparentsubstrate 100 can be reflected by the reflective layer 510 and return tothe semiconductor layer 110, so the semiconductor layer 110 can generatelarger photocurrent. In some embodiments, the ratio of photocurrent todark current generated by the semiconductor layer 110 is greater than orequal to two orders of magnitude.

The doping type of the semiconductor layer 110 will influence thedirection of the current generated after the PIN diode is irradiated. Inthis embodiment, the first doping region 112 is an N-type semiconductor,the second doping region 116 is a P-type semiconductor, and the surfacesof the induced polarized particles 300 are negatively charged. In otherembodiments, the first doping region 112 is a P-type semiconductor, thesecond doping region 116 is an N-type semiconductor, and the surfaces ofthe induced polarized particles 300 are positively charged.

FIG. 3A to FIG. 9A, FIG. 10 , FIG. 11 and FIG. 12 are schematiccross-sectional views of a method for manufacturing an optical tweezerdevice according to an embodiment of the present invention. FIG. 3B toFIG. 9B are schematic top views of the structures of FIG. 3A to FIG. 9A.It should be noted herein that, in embodiments provided in FIG. 3A toFIG. 9A, FIG. 10 , FIG. 11 and FIG. 12 , element numerals and partialcontent of the embodiments provided in FIG. 1A, FIG. 1B and FIG. 2 arefollowed, the same or similar reference numerals being used to representthe same or similar elements, and description of the same technicalcontent being omitted. For a description of an omitted part, referencemay be made to the foregoing embodiment, and the descriptions thereofare omitted herein.

Referring to FIG. 3A and FIG. 3B, a semiconductor material layer 110 ais formed above the transparent substrate 100. In this embodiment, sincethe semiconductor material layer 110 a is located above the transparentsubstrate 100, the semiconductor material layer 110 a can be formed by athin film process, thereby reducing the production cost of the opticaltweezer device. In some embodiments, the method for forming thesemiconductor material layer 110 a includes, for example, a lowtemperature poly-silicon (LIPS) process or other suitable processes. Inaddition, compared with fabricating the optical tweezer device on awafer, a large-area optical tweezer device can be easily obtained byusing the thin film process.

Referring to FIG. 4A to FIG. 5A and FIG. 4B to FIG. 5B, multiple dopingprocesses are performed on the semiconductor material layer 110 a toform the semiconductor layer 110 including the first doping regions 112,the second doping region 116 and the transition regions 114, wherein thetransition regions 114 are located between the first doping regions 112and the second doping region 116.

Referring to FIG. 4A and FIG. 4B, a first mask pattern PR1 is formedabove the first regions R1 of the semiconductor material layer 110 a,and the first mask pattern PR1 exposes the second region R2 and thethird regions R3 of the semiconductor material layer 110 a, the firstregions R1 surround the third regions R3, and the first regions R1 arelocated between the second region R2 and the third regions R3. In someembodiments, the first mask pattern PR1 is, for example, a patternedphotoresist.

Using the first mask pattern PR1 as a mask, a first doping process isperformed on the second region R2 and the third regions R3 of thesemiconductor material layer 110 a to form the semiconductor materiallayer 110 a. The first doping process is, for example, a P-type dopingor an N-type doping. In this embodiment, the first doping process is aP-type doping process. In this embodiment, the first doping processforms the second doping region 116 and the first doping region 112 awith the same doping type in the second region R2 and the third regionR3.

After the first doping process is performed, the first mask pattern PR1is removed. In some embodiments, the first mask pattern PR1 is removedby etching (e.g., ashing).

Referring to FIG. 5A and FIG. 5B, a second mask pattern PR2 is formedabove the first regions R1 and the second region R2 of the semiconductormaterial layer 110 a, and the second mask pattern PR2 exposes the thirdregions R3 of the semiconductor material layer 110 a. In someembodiments, the second mask pattern PR2 is, for example, a patternedphotoresist.

Using the second mask pattern PR2 as a mask, a second doping process isperformed on the third region R3 of the semiconductor material layer 110a. The second doping process is, for example, a P-type doping or anN-type doping. In this embodiment, the second doping process isdifferent from the first doping process, and the second doping processis an N-type doping process. In this embodiment, the second dopingprocess forms the first doping regions 112 in the third regions R3.

So far, the semiconductor layer 110 including the first doping regions112, the second doping region 116 and the transition regions 114 issubstantially completed, the third regions R3 of the semiconductormaterial layer 110 a corresponds to the position of the first dopingregions 112, the second region R2 of the semiconductor material layer110 a corresponds to the position of the second doping region 116, andthe first regions R1 of the semiconductor material layer 110 acorresponds to the position of the transition regions 114.

After performing the second doping process, the second mask pattern PR2is removed. In some embodiments, the second mask pattern PR2 is removedby etching (e.g., ashing).

Referring to FIG. 6A and FIG. 6B, an insulation material layer 120 a isformed on the semiconductor layer 110. In some embodiments, theinsulation material layer 120 a includes silicon oxide, silicon nitride,silicon oxynitride, or other suitable materials.

In some embodiments, hydrogen element is included in the insulationmaterial layer 120 a, and an annealing process is performed on thesemiconductor layer 110 and the insulation material layer 120 a, so thatthe hydrogen element in the insulation material layer 120 a is diffusedto the semiconductor layer 110, thereby repairing the damage ofsemiconductor layer 110 generated during the doping process. In someembodiments, the aforementioned annealing process is heating thesemiconductor layer 110 and the insulating material layer 120 a to atemperature of 400 degrees Celsius to 625 degrees Celsius by a rapidthermal annealing process.

Referring to FIG. 7A and FIG. 7B, the insulation material layer 120 a ispatterned to form the insulation layer 120 exposing the first dopingregions 112 and the second doping region 116. In this embodiment, athird mask pattern PR3 is formed on the insulation material layer 120 a.Using the third mask pattern PR3 as a mask, the insulation materiallayer 120 a is etched to form the insulation layer 120 including theopenings O1 and O2. The openings O1 of the insulation layer 120 exposethe first doping regions 112, and the opening O2 of the insulation layer120 expose the second doping region 116. In some embodiments, the thirdmask pattern PR3 is, for example, a patterned photoresist.

In some embodiments, after the insulation material layer 120 a ispatterned, the third mask pattern PR3 is removed. In some embodiments,the third mask pattern PR3 is removed by etching (e.g., ashing).

Referring to FIG. 8A and FIG. 8B, the first electrodes E1 are formed onthe first doping regions 112, and a second electrode E2 is formed on thesecond doping region 116. In some embodiments, the first electrodes E1and the second electrode E2 belong to the same conductive film layer.For example, the method for forming the first electrodes E1 and thesecond electrode E2 includes: forming a conductive material layer on theinsulation layer 120, and filling the conductive material layer into theopenings O1 and O2 of the insulation layer 120, and then patterning theconductive material layer material layer to form the first electrodes E1and the second electrode E2 which are separated from each other.

Referring to FIG. 9A and FIG. 9B, a dielectric layer 130 is formed onthe semiconductor layer 110. In this embodiment, the dielectric layer130 is formed on a part of the first electrodes E1, the second electrodeE2 and the insulation layer 120. The dielectric layer 130 has firstthrough holes 132 overlapping the first electrodes E1, and thedielectric layer 130 covers the top surface of the second electrode E2.

Referring to FIG. 10 , a protection adhesive layer 140 is formed abovethe dielectric layer 130. In some embodiments, the protection adhesivelayer 140 is filled in the first through holes 132 of the dielectriclayer 130. In some embodiments, the protection adhesive layer 140includes peelable adhesive.

Referring to FIG. 11 , a reflective layer 510 is formed on the side ofthe transparent substrate 100 opposite to the semiconductor layer 110.Then, a protection layer 520 is formed on the reflective layer 510. Forexample, the reflective layer 510 is formed on the transparent substrate100 over the entire surface, but the present invention is not limitedthereto. In some embodiments, the reflective layer 510 is a patternedfilm layer.

Referring to FIG. 12 , the protection adhesive layer 140 is removed.After removing the protection adhesive layer 140, the counter electrode400 overlapping the first electrodes E1 is provided; the buffer solution200 is provided between the counter electrode 400 and the firstelectrodes E1 and between the counter electrode 400 and the dielectriclayer 130; and a plurality of particles 300 are provided in the buffersolution 200, as shown in FIG. 1B. So far, the optical tweezer device 10is substantially completed.

FIG. 13A is a schematic cross-sectional view of an optical tweezerdevice according to an embodiment of the present invention. FIG. 13B isa schematic top view of the optical tweezer device of FIG. 13A. Itshould be noted herein that, in embodiments provided in FIG. 13A andFIG. 13B, element numerals and partial content of the embodimentsprovided in FIG. 1A, FIG. 1B and FIG. 2 are followed, the same orsimilar reference numerals being used to represent the same or similarelements, and description of the same technical content being omitted.For a description of an omitted part, reference may be made to theforegoing embodiment, and the descriptions thereof are omitted herein.

The difference between the optical tweezer device 20 of FIG. 13A andFIG. 13B and the optical tweezer device 10 of FIG. 1A and FIG. 1B isthat: the positions of the N-type semiconductor and the P-typesemiconductor in the semiconductor layer 110 of the optical tweezerdevice 10 are different from the positions of the N-type semiconductorand the P-type semiconductor in the semiconductor layer 110A of theoptical tweezer device 20. The first doping regions 112 and the seconddoping region 116 in the semiconductor layer 110 of the optical tweezerdevice 10 are N-type semiconductors and a P-type semiconductorrespectively, while the first doping regions 112A and the second dopingregion 116A in the semiconductor layer 110A of the optical tweezerdevice 20 are P-type semiconductors and an N-type semiconductorrespectively.

In the embodiments of FIG. 13A and FIG. 13B, the first electrodes E1 areelectrically connected to the P-type semiconductors, and the secondelectrode E2 is electrically connected to the N-type semiconductor. Inthis embodiment, the surface of the induced polarized particles 300 ispositively charged.

FIG. 14A is a schematic cross-sectional view of an optical tweezerdevice according to an embodiment of the present invention. FIG. 14B isa schematic top view of the optical tweezer device of FIG. 14A. Itshould be noted herein that, in embodiments provided in FIG. 14A andFIG. 14B, element numerals and partial content of the embodimentsprovided in FIG. 1A, FIG. 1B and FIG. 2 are followed, the same orsimilar reference numerals being used to represent the same or similarelements, and description of the same technical content being omitted.For a description of an omitted part, reference may be made to theforegoing embodiment, and the descriptions thereof are omitted herein.

The difference between the optical tweezer device 30 of FIG. 14A andFIG. 14B and the optical tweezer device 10 of FIG. 1A and FIG. 1B isthat: the semiconductor layer 110 of the optical tweezer device 10includes PIN diodes, while the semiconductor layer 110B of the opticaltweezer device 20 includes PN diodes.

In the embodiment of FIG. 14A and FIG. 14B, the first doping regions112B and the second doping region 116B in the semiconductor layer 110Bare N-type semiconductors, and the transition regions 114B are P-typesemiconductor. In the embodiment shown in FIG. 14A and FIG. 14B, thefirst electrodes E1 and the second electrode E2 are both electricallyconnected to the N-type semiconductors.

In this embodiment, when the light beam is irradiated to the PN diode,the PN diode will generate a photocurrent, thereby attracting orrepelling the particles 300.

FIG. 15A is a schematic cross-sectional view of an optical tweezerdevice according to an embodiment of the present invention. FIG. 15B isa schematic top view of the optical tweezer device of FIG. 15A. Itshould be noted herein that, in embodiments provided in FIG. 15A andFIG. 15B, element numerals and partial content of the embodimentsprovided in FIG. 1A, FIG. 1B and FIG. 2 are followed, the same orsimilar reference numerals being used to represent the same or similarelements, and description of the same technical content being omitted.For a description of an omitted part, reference may be made to theforegoing embodiment, and the descriptions thereof are omitted herein.

The difference between the optical tweezer device 40 of FIG. 15A andFIG. 15B and the optical tweezer device 10 of FIG. 1A and FIG. 1B isthat: the semiconductor layer 110 of the optical tweezer device 10includes PIN diodes, while the semiconductor layer 110C of the opticaltweezer device 40 includes PN diodes.

In the embodiment of FIG. 15A and FIG. 15B, the first doping regions112C and the second doping region 116C in the semiconductor layer 110Care P-type semiconductors, and the transition regions 114C are N-typesemiconductors. In the embodiment shown in FIG. 15A and FIG. 15B, thefirst electrodes E1 and the second electrode E2 are both electricallyconnected to the P-type semiconductors.

In this embodiment, when the light beam is irradiated to the PN diode,the PN diode will generate a photocurrent, thereby attracting orrepelling the particles 300.

What is claimed is:
 1. An optical tweezer device, comprising: atransparent substrate; a semiconductor layer, located above thetransparent substrate and comprising a first doping region, a seconddoping region and a transition region, wherein the transition region islocated between the first doping region and the second doping region; afirst electrode, located on the first doping region and electricallyconnected to the first doping region; and a dielectric layer, locatedabove the semiconductor layer and having a first through holeoverlapping the first electrode.
 2. The optical tweezer device of claim1, further comprises: a second electrode, located on the second dopingregion and electrically connected to the second doping region.
 3. Theoptical tweezer device of claim 2, wherein the first electrode is anisland-shaped structure, and the second electrode surrounds the firstelectrode.
 4. The optical tweezer device of claim 2, wherein thedielectric layer covers a top surface of the second electrode.
 5. Theoptical tweezer device of claim 1, wherein the second doping regionsurrounds the transition region.
 6. The optical tweezer device of claim1, wherein one of the first doping region and the second doping regionis a P-type semiconductor, another of the first doping region and thesecond doping region is an N-type semiconductor, and the transitionregion is an intrinsic semiconductor or a lightly doped semiconductorwhich has a purity close to the intrinsic semiconductor.
 7. The opticaltweezer device of claim 1, wherein the first doping region and thesecond doping region are P-type semiconductors, and the transitionregion is an N-type semiconductor or a lightly doped semiconductor whichhas a purity close to an intrinsic semiconductor.
 8. The optical tweezerdevice of claim 1, wherein the first doping region and the second dopingregion are N-type semiconductors, and the transition region is a P-typesemiconductor or a lightly doped semiconductor which has a purity closeto an intrinsic semiconductor.
 9. The optical tweezer device of claim 1,further comprises: a reflective layer, wherein the transparent substrateis located between the reflective layer and the semiconductor layer. 10.The optical tweezer device of claim 1, further comprises: an insulationlayer, located between the dielectric layer and the semiconductor layer;a counter electrode overlapping the first electrode; a buffer solution,located between the counter electrode and the first electrode; and aplurality of particles, located in the buffer solution.
 11. Amanufacturing method of an optical tweezer device, comprising: forming asemiconductor material layer above a transparent substrate; performing aplurality of doping processes on the semiconductor material layer toform a semiconductor layer including a first doping region, a seconddoping region and a transition region, wherein the transition region islocated between the first doping region and the second doping region;forming a first electrode on the first doping region; and forming adielectric layer above the semiconductor layer, wherein the dielectriclayer has a first through hole overlapping the first electrode.
 12. Themanufacturing method of the optical tweezer device of claim 11, furthercomprising: forming a second electrode on the second doping region,wherein the first electrode and the second electrode belong to a sameconductive film layer, and the dielectric layer covers a top surface ofthe second electrode.
 13. The manufacturing method of the opticaltweezer device of claim 11, further comprises: forming a protectionadhesive layer on the dielectric layer; forming a reflective layer on aside of the transparent substrate facing away from the semiconductorlayer; and removing the protection adhesive layer.
 14. The manufacturingmethod of the optical tweezer device of claim 13, wherein the protectionadhesive layer is filled in the first through hole.
 15. Themanufacturing method of the optical tweezer device of claim 11, furthercomprises: forming an insulation material layer on the semiconductorlayer; performing an annealing process on the semiconductor layer andthe insulation material layer to make hydrogen in the insulationmaterial layer diffuse to the semiconductor layer; and patterning theinsulation material layer to form an insulation layer exposing the firstdoping region and the second doping region, wherein the dielectric layeris formed on the insulation layer.
 16. The manufacturing method of theoptical tweezer device of claim 11, performing the plurality of dopingprocesses on the semiconductor material layer comprises: forming a firstmask pattern on a first region of the semiconductor material layer;using the first mask pattern as a mask, performing a first dopingprocess on a second region and a third region of the semiconductormaterial layer; forming a second mask pattern on the first region andthe second region of the semiconductor material layer; using the secondmask pattern as a mask, performing a second doping process on a thirdregion of the semiconductor material layer, wherein the third regioncorresponds to the position of the first doping region, the secondregion corresponds to the position of the second doping region, and thefirst region corresponds to the position of the transition region. 17.The manufacturing method of the optical tweezer device of claim 11,further comprises: providing a counter electrode overlapping the firstelectrode; providing a buffer solution between the counter electrode andthe first electrode; and providing a plurality of particles in thebuffer solution.
 18. The manufacturing method of the optical tweezerdevice of claim 11, wherein the second doping region surrounds thetransition region.